NOTES FOR STAR-OF-BETHLEHEM ------------------------- John Pazmino NYSkies Astronomy Inc www.nyskies.o firstname.lastname@example.org 2002 December 21
[Dates are Julian Universal Time. Dates may differ slightly from other calcs due to algorithms and definitions]
year date event ------- ------ -------------------- early birth events ------------------ 7BC, -6 May 29 Jupiter-Saturn conjunction Jul 7 Saturn western station Jul 17 Jupiter western station Sep 14 Saturn opposition Sep 15 Jupiter opposition Sep 30 Jupiter Saturn conjunction Nov 12 Jupiter eastern station Nov 20 Saturn eastern station Dec 12 Jupiter-Saturn conjunction 6BC, -5 Feb 20 Moon-Mars conjunction Moon-Jupiter conjunction Moon-Saturn conjunction Moon-Mars-Jupiter-Saturn convention Mars-Saturn conjunction Mar 4 Mars-Jupiter conjunction Mar xx nova in Aquila-Capricornus Apr 17 Moon-Jupiter occultation Jul xx nova in Cygnus [these MAY be rally a comet moving from Capricornus to Cygnus, lasting 70 days, OR nova misplaced but still lasting 70 days] Aug 22 Jupiter western station Oct 21 Jupiter opposition Nov 16 Jupiter eastern station
Herodus's events ---------------- 4BC, -3 Mar 13 partial lunar eclipse 1BC, 0 Jan 10 total lunar eclipse 1BC 0 Dec 29 partial lunar eclipse
late birth events ----------------- 4BC, -3 May 18 Venus-Mars conjunction May 24 Venus-Jupiter conjunction May 24 Venus-Mars-Jupiter convention May 31 Mars-Jupiter conjunction 3BC, -2 Aug 11 Moon-Venus-Jupiter convention Aug 12 Venus-Jupiter conjunction Sep 13 Jupiter-Regulus conjunction Nov 27 Jupiter western station 2BC, -1 Jan 26 Jupiter opposition Feb 18 Jupiter=Regulus conjunction Mar 29 Jupiter eastern station May 7 Jupiter-Regulus conjunction Jun 17 Jupiter-Venus consolidation Aug 31 Moon-Venus-Mars-Jupiter convention
modern events (Gregorian dates) ------------------------------ 1779AD Nov 9 Mira brightest maximum of 1.3 magnitude 1972AD xxx xx Enif flareup to 0.9 magnitude 1980AD Dec 31 Jupiter-Saturn conjunction 1981AD Jan 2 JUpiter western station Jna 18 Saturn western station Jan 24 Jupiter western station Mar 4 Jupiter-Saturn conjunction Mar 26 Jupiter opposition Mar 27 Saturn opposition May 27 Jupiter eastern station Jun 5 Saturn eastern station Jul 24 Jupiter-Saturn conjunction 1994AD Jul xx Jupiter-SL9 collision 1998AD Apr 23 Moon-Jupiter occultation, with Venus Apr 23 Moon-Venus occultation, with Jupiter 2000AD Feb xx Dschubba flareup to 1.8 magnitude
[Not exhaustive, but I touched the important points]
Years are numbers in the BC era in two ways. The historical or chronological method starts with '1BC' for the year preceding 1AD. The numbering continues backwards into the past from there. There is NO year number '0'. The astronomical or algebraic method counts with a year '0' and past years are negative numbers. Lo here the timeline for comparison.
-7 -6 -5 -4 -3 -2 -1 0 1 2 >--|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|--> 8BC 7BC 6BC 5BC 4BC 3BC 2BC 1BC 1AD 2AD
Note that the 'BC' year is one GREATER in absolute value than the 'minus' year. You MUST understand how your planetarium program treats years in the BC era to set it correctly for Christmas Star simulations. I don't know, and can't find any one who knows, why AD is Latin and BC is English. I have seen 'AC' for 'ante Christo' for BC years.
The calendar in force across the BC/AD period was the Julian, not Gregorian, calendar. The contemporary calendar was a bit out of joint from political tampering and lack of modern concepts of 'history'. All dates are now established by a copasetic Julian calendar. For studies before the Julian calendar (about -45 or 46BC) we prolong the Julian calendar backwards, even tho the 'date' is then entirely fictitious. That's why you can read of some Japanese eclipse on, made up, 1234BC January 8, when there simply was no such a date in existence so far long ago. The days of the week are generally missed out in the BC era for astronomy purposes. However, the week cycles thru the seven days without interruption or shuffling regardless of what happens to the calendar date.
Planetarium programs MUST have longterm dynamics for the planetary motions and precession. Using a program with 'trolley track' orbits and a simple precession will yield erroneous simulations. Some programs specify the range of valid years; HNSky, for instance, will NOT work for years before 1750. Others don't trap invalid dates but will then display all wrong skies. The program MUST be fed contemporary comet orbit elements. You can NOT just change the perihelion date of a modern orbit. SkyMap, Starry Night, Dance, SkyGlobe, Expert Astronomer are examples of good planetarium programs.
Jerusalem is at latitude 31 degrees north, longitude 48 degrees east, rounded. A shift eastward in longitude only affects the hour of a sky display. You may pick from your planetarium's city list any place in Israel, Jordan, Iraq, or Iran. These modern countries are in the path presumably taken by the Magi, who likely (but hardly certainly!) came from either Babylonia or Persia.
The delta-T correction, the offset of Universal Time from the Atomic Time, may be ignored. Your planetarium may work with a lookup value or may be lack a delta-T feature.
The one and only account of the Star is in book of Matthew. There is no other independent record of the Star, only commentary based on Matthew. Matthew does not say anything about: the brilliance of the Star the size, shape, changes of the Star which segment of the day the Star was seen how many Magi came to Bethlehem where specificly the Magi came from the time frame for the Magi's trip Any assertions about these features comes from external considerations, not as yet certainly founded in history.
The Star could be a single celestial event or a series of events. It may be an interpretation of some reproducible predictable event, or one which was unpredictable and now nonreproducible. On the other hand the Star could be a truly other-worldly apparition or a total fabrication.
Astrology may be a weak feature in the Christmas Star story because the magi were basing their trip on the Jewish scriptures and Jewish faith. Faithful Jews did not practice astrology The magi, coming from (presumably) a nonJewish territory still practicing astrology, may have blended Jewish teachings with astrology. More over, there was no monolithic 'astrology' at that time, but a variety of practices, each with its own lore and methods
Alignments of planets would have been closely, if not accurately, predictable at that time. Almanacs were good enough from Babylonian and Greek astronomy. The magi were not seeing, among the planets, unknowable or unpredictable events. They may have studied the planets to improve their almanacs or to satisfy themselfs that the almanacs were working.
The date of the Nativity is STILL very much unsettled. There are two schools, the 'early birth' and 'late birth'. The former sets the Nativity in 6BC (+/- 1 year). The latter puts it in 2BC (+/- 1 year). The cause is the dispute over when Herodus died. Matthew says the Nativity occurred during Herodus's reign, which ended in EITHER 4BC or 1NC. The dispute is about which of two lunar eclipses immediately preceded his death.
The present AD count of year wasn't started until about 540AD, by which time memory and records may have been lost. This period was the initial throes of the Dark Ages, following the collapse of the Roman empire in the west. It was also the beginning of the Byzantine era in the east. As careful as the counting was done, errors easily could have slipped in. There was provision for a zero year and, in fact, there was no notion to extend the count before the Nativity.
It REALLY helps to know Latin, to understand documents, coins, monuments, and the like in reading up on the Star of Bethlehem.